Features of Pathogens, Epidemiology, and Diagnosis of COVID-19 and Reliable Suggestion: Aiming to Solve the Confusion in Clinical Practice

In past several months, the worldwide outbreak of COVID-19 infection is unstoppable, which results in millions of people infected and thousands of people dead. However, there are still something controversial in the virus mechanism, the epidemiological feature and the diagnose criterion of COVID-19, while we also have some consensus. The structure of SARS-CoV-2, the pathogen of COVID-19, is roughly similar with other coronavirus such as SARS-CoV and bat-CoV, but by sequencing the amino acid, recombination of virus particles, and observation in Electron microscope, it is obvious to find the some slight difference between the protein of SARS-CoV-2 and others’. The spike protein of SARSCoV-2 has a stronger ability to binding ACE2 than SARS-CoV. The carrier of SARS-CoV-2 is just as other respiratory viruses, like droplet, aerosol and surface, and the fecal-oral transmission is proved to be an efficient pathway. In clinical practice, the elder and the patients with comorbidity are more susceptible to infection and have poorer prognosis, while pediatric patients is the very opposite of it. Nucleic acid test represented by RT-PCR is a helpful method for diagnose, yet it has weaknesses of false negative in suspicious patient and resurgence in discharge patient. Serological and immunological test, reported not suitable for diagnose alone in early period, can be another reliable method that benefit the accuracy of diagnosis criterion when combined with RT-PCR.